# NTSB NYC83FU001: Pterodactyl Ascender II, Lehighton, PA, March 31, 1983

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Final report
- Date: March 31, 1983, 15:00 local (20:00 UTC)
- Place: Lehighton, PA
- Coordinates: 40.829143, -75.709327 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=40.8291&lon=-75.7093&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 35123
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC83FU001
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/35123/pdf
- Page: https://openairdocs.org/ntsb/NYC83FU001

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of control - in flight, maneuvering
  - aircraft handling - not maintained, pilot in command (cause)
  - lack of familiarity with aircraft, pilot in command (contributing factor)
- Airframe/component/system failure/malfunction, maneuvering
  - flight controls - improper use of, pilot in command (cause)
  - design stress limits of aircraft - exceeded, pilot in command (cause)
  - wing - overload (contributing factor)
  - wing,spar - bent (contributing factor)
  - wing,winglet - separation (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

SEVERAL WITNESSES OBSERVED THE ULTRALIGHT VEHICLE TAKEOFF & CLIMB IN A CIRCULAR PATTERN TO AN ALT OF ABOUT 1500 FT. ONE WITNESS STATED THAT JUST PRIOR TO THE ACCIDENT SEQUENCE, THE ULTRALIGHT WAS TURNING WITH A STEEP ANGLE OF BANK. AT ABOUT THAT TIME, THE WITNESSES HEARD A REDUCTION IN POWER. TWO WITNESSES HEARD A POP/PUFF SOUND. A 3RD WITNESS STATED THE ULTRALIGHT FLIPPED OVER TWICE. ALL 3 WITNESSES REPORTED THAT THE WINGS FOLDED OR COLLAPSED & THE ULTRALIGHT FELL OR DOVE TO THE GROUND. AN EXAM OF THE WRECKAGE REVEALED THAT THE LEADING EDGE & REAR TUBULAR SPARS HAD FAILED IN A DOWNWARD DIRECTION (RELATIVE TO THE AIRFRAME). ALSO, THE KEEL WAS BROKEN, FORWARD OF THE REAR SPARS & THE KING POST WAS BENT DOWNWARD AT ABOUT THE MIDPOINT. NONE OF THE CABLES FAILED. DURING THE ACCIDENT SEQUENCE, THE RIGHT WINGLET SEPARATED & FELL ABOUT 100 FT FROM THE MAIN WRECKAGE.

## Aircraft

- Registration: UNREG (not matched to a registry record)
- Reported make and model: PTERODACTYL ASCENDER II (ASCENDER I)
- Category: Ultralight, amateur-built
- Serial number: 1239
- Airframe hours: 4
- Engines: CUYUNA 14119 30 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 103
- Registered owner: John F. Gibbons
- Departed: LEHIGHTON, PA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 35; airplane ratings: single-engine land; medical: unknown, unknown; seat: center; flight hours: 4 total, 4 in this make and model, 4 as pilot in command, 4 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 120° at 7 knots
- Visibility: 20 statute miles
- Lowest ceiling: none
- Temperature: 48 °F, dew point 12 °F
- Altimeter: 29.00 inHg
- Observed at: ABE

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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